Absorption refrigerating apparatus



' May 27,1941.

H. L, SCHUG ABS ORPTION REFRIGERATING ABPARATUS 3 Sheets-Sheet 1 oriinal Filed Mai-ch 15, 1939 Howard L. Sella ATTORNEY May 27, 1941. H.SCHUG ABSORPTION REFRIGERATING APPARATUS 5 Sheets-Sheet 2 Original FiledMarch l3, 1939 A @Wi.

lzbwafd 1. Schuj ATTORNEY y 27, 1- 1-1. L. SCHU G Re. 21,812

ABSORPTION REFRIGERATING APPARATUS Original Filed March 15', 1939 5Sheets-Sheet 3 )Yowafd 1,. my

I ATTORNEY Reissued May 27, 1941 Howard L. Schng, North Canton, Ohio,'assignor to The Hoover Company, North Canton, Ohio, a

corporation of Ohio Original No. 2,204,233, dated June 11, 1940, SerialNo. 261,478, March 13, 1939. Application for reissue November 12, 1940,Serial No. 365,397

9 Claims. (Cl. 62-1195) This application is a continuation-impart ofapplication, Serial No. 25,732, filed June 10, 1935.

This invention relates to continuous absorption refrigerating apparatusof the type in which an inert gas is employed and more particularly tonovel means for circulating the inert gas, as well as a novel manner ofincorporating a gas circulator in a refrigerating apparatus.

Continuous absorption refrigerating systems in which an inert gas isemployed and in which it is circulated by power-driven means 'such as afan have been proposed heretofore, but have not been perfected. In orderto circulate the inert gas by means of a fan, however, it is necessaryto extend the fan shaft through a wall of the apparatus to a drivingmotor. This presents the disadvantage that the apparatus is liable toleak, especially after the parts which move have become worn. It alsopresents the problem of providing a structure in which the apparatuswill have long life .since the bearings ior the shaft are apt to corrodeespecially if subjected to fluids in..th e system which have a corrosiveeflect upon the metals employed.

It is one object of the present invention .to provide an improved gascirculating means Y adapted for use in absorption refrigerating systemsbut in which the disadvantages and the detects cited by way of examplehereinabove are overcome.

In absorption refrigerating apparatus using ammonia as areirlgeranhwateras the absorbent.

and hydrogen or nitrogen as the inert medium, the normal operatingpressures are in the neigh borhood of from 250# to 300# per-square inch.To eliminate leakage from the system under motors circulator unitwherein the moving parts of the unit are hermetically sealed within thewalls of the system and in which the field structure of the motor ispositioned outside thewalls of the system.

The best path for magnetic lines of force is one made of magneticmaterial. Furthermore, the interposition of non-magnetic material willsubstantially confine the flux to the magnetic material or offerresistance to the passage of magnetic flux it positioned in the normalpath of the flux. These principles are applied to achieve features ofthe present invention, as-will appear more clearly from a detaileddescription of the invention hereinbelow. Absorption refrigeratingapparatus using am monia as a refrigerant and water as the absorbent areusually constructed of heavy steel tubing of sufllcient strength towithstand the high pressures within the system. This steel tubing isusually of a highly magnetic material. In associating a motor circulatorunit of the present type with such a system, it is necessary to devisesome w to provide an inert gas circulating unit for a these highpressures, it has been proposed to hermetically seal the moving parts ofthe medium circulating unit within the walls of the system.

This necessitates either the positioning of the entire motor within thesystem or in positioning the moving parts of the motor pump unit insidethe walls of the system and the positioning 0! the motor iield structureoutside the system. In

- the former case, special precautionsmustbe taken to protect the fieldwindings from the corrosive action'ot the refrigerant. In the lattercase, the walls between the moving of the motor and modem structure mustbe of sumclent strength to withstand the pressures within the system,and at the same time provision must be made for conducting. the magneticflux through the walls of the system without magnetic flux leakage toother parts 01' the system.

The present invention is concerned with 8 05 means of extending thefield core through the heavy steel tubing and at the same timeseparatethe field structure from the remainder of the steel tubing making up thesystem walls by means of. non-magnetic material of sufllcient strengthand so secured to the steel tubing making up the system walls as to becapable of withstan the high pressures within the system.

It is erefore another object of this invention three-fluid absorptionrefrigerating apparatus in which the moving parts of the circulator unitare hemetically sealed within the walls of the system and the fieldstructure is located outside the system walls. More specifically, it isan object toprovide a motor unit in which the ileld core extends throughthe tubing forming the system walls or communicates with the interior oisaid system by a path of magnetic material and is separated from theremainder of the walls of the system by non-magnetic material. Theportion of the fleld core extending through the system walls is securedtothe tubing in sucha' waythatitiorms a partoithewalls ofthe system, andat the same time provides an eilicient path for the magnetic fluxexcited by the field coilsthroughthewallsoithesystem,soasto exert amoving force to the moving parts of the circulator unit without unduemagnetic flux leakage into the remainder of the system walls.

- It is another object of this inventionto .provide an inert gascirculator unit for an absorprelation as illustrated.

tion refrigerating apparatus in which the moving parts of the circulatorunit are hermetically sealed within the walls of the system and thefield structure is positioned outside the system walls wherein a portionof the system walls forms both a mechanical and an electrical function.

In an absorption refrigerating apparatus of the type using an inertpressure equalizing medium,

, it may sometime happen that all of the refrigerant supplied to theevaporator is not evapo- Other objects and advantages reside in cer--tain novel features of the arrangement and con-- struction of parts aswill be apparent from the following description taken in connection withthe accompanying drawings, in which:

Figure 1 is a diagram of a continuous absorption refrigerating system inwhich one form of inert medium circulating unit according to the presentinvention is incorporated;

Figure 2 is a vertical cross-sectional view of the gas circulating unitas shown in Figure l;

Figure 3 shows the diagram of a continuous absorption refrigeratingsystem of Figure 1 partly broken away to show another form of gascirculator unit incorporated as an integral part of the absorber;

-Figure 4 shows a vertical cross-sectional view or another form of gascirculator unit; and

Figure 5 is a perspective view of the gas circulator unit of Figure 4.

Referring to the drawings indetail and first to the diagrammaticillustration in Figure 1, it will be seen that a continuous absorptionrefrig-q erating system is illustrated as consisting of a boiler B, avapor separation chamber S, a condenser C', an evaporator E, and anabsorber A as essential elements, these devices being connected by anumber of conduits to form the complete refrigerating system.

The boiler B is connected to the vapor separation chamber S by means ofthe conduit ll which may act as a vapor lift pump to convey bothabsorption liquid and refrigerant vapor into the vaporseparation.chamber S. From this chamber the liquid flows into theabsorber A through the U-shaped conduit II. The absorber A may consistmerely of a vertical tank with a number of bailie plates therein. Theabsorption liquid supplied to the upper end thereof by the conduit l2trickles downwardly over the baiiies and leaves the absorber through theconduit l3 through which it flows back to the boiler B.

The conduits l2 and I! may be in'heat exchange Refrigerant vaporgenerated in the boiler 13,

the conduit II, or the vapor separation chamber S passes upwardlythrough a conduit ll,- a portion of which may :act as a rectifier, andinto the condenser C; The condenser C may consist merely of a coil ofpipe so arranged that the refrigerant ,vapor supplied thereto. upon be'75 duit I6 having a gas circulating device or pump,

represented generally by the reference number I I8, incorporatedtherein. As illustrated in Figure 1, the conduit l6 connects the top ofthe absorber to the bottom of the evaporator. The conduit l1, ontheother hand, connects the top of the evaporator to the bottom of theabsorber. The conduits l6 and II can be in heat exchange relation over aportion of their path as illustrated in Figure 1.

When inert gas is circulated between the evaporator and the absorber,the refrigerant supplied to the evaporator in liquid form evaporates bydiffusion into the inert medium to produce the cooling effect and isconveyed into the absorber where it is absorbed by the absorption liquidflowing therethrough and thus returned to the boiler B.

In accordance with known practices, water may be used as the absorptionliquid, ammonia as the refrigerant, and hydrogen as the inert gas in theevaporator and the absorber.

In order to prevent any liquid which may not have evaporated in theevaporator E or liquid which may have condensed in conduit it frominterfering with the proper operation of the gas circulating device 18,a small liquid conduit l9 may be connected to the lower portion of theconduit i6 and to the absorber to drain any liquid from this conduitinto the absorber.

The gas circulating unit I8 01' Figure 1 is shown in detail in Figure 2.The circulator unit consists of a casing 20, the lower portion of whichforms a part of the conduit l8 and the upper portion 2| which is ofcup-shaped formation secured to the lower portion by bolts 22. Securedbetween the upper and lower portions of the casing is a. diaphragm 23with concentric ribs 24 pressed upwardly therein. Secured to the upperside of the diaphragm 23 is an armature 25 and integrally secured to thebottom of the diaphragm is a jet nozzle 26. Extending laterally from theupper portion 2| oi the casing 20 and through the walls-of the upwardlyextending portions 21 'of the tube 6 is a second jet nozzle 28.

Secured to the upper portion 2| of the casing 20 is a field core 29 inthe form of an annular cup having a leg 30 extending through the upperwall it of the casing. The leg 30 of the magnetic core 29 is separatedfrom the remainder of the walls of the casing by an annular insert 32 ofnonmagnetic material. As shown the leg III has a tapered portion at itslower end and the insert 32 is tapered so as to make good contact withthe portion II of the casing after the fleld'core is assembled so astowithstand the high pressures within the system. If thought desirable,the leg 10 and the non-magnetic insert 32 may be welded in position. Theleg ll] of the magnetic core is surrounded by an energizing-coil II. Theleg 30 of the magnetic core may be in the form of a stud bolt and theremainder of the core made of laminated sheets of magnetic material,suitably secured-against the outer end of the leg 30 so that whenalternating current is supplied" to the coil 33, a magnetic circuit isset up. The

magnetic circuit includes the leg 30, the outer core piece 28, theportion 3| of the casing 2i the outer ends of the field core 25 may bemade I of magnetic material, the remainder, as shown at 34, being madeof non-magnetic material. In either construction, annulus 32 maycomprise any suitable non-magnetic material, although I prefer to useone of the non-magnetic stainless steels. The inserts torm an essentialpart of the refrigeration apparatus wall and are secured in placetherein by welding.

As shown in the accompanying drawings, cap 2| forms a portion of thewalls of the system and comprisesa circular magnetic portion 80, anannular non-magnetic portion 32, an annular portion 3| of magneticmaterial and a second nonmagnetic annular portion 34. With thisconstruction a strong magnetic field is set up tem walls by non-magneticmaterial so as to prevent undue magnetic flux leakage. Since theportions in and II of the magnetic field core circuit form a part of thesystem walls, they perthrough the armature without undue magnetic fluxleakage to other parts oi the system and in additiomthere is no dangerof leakage of gases through the walls of the casing member 2| sincethere is but one opening in this casing tightly sealed by thenon-magnetic insert 32 and the leg 38 of the field, core.

As the diaphragm 23 is vibrated back and forth by the electro-magneticmeans, the volume of the chamber between the diaphragm 23 and the cupmember 2| changes slightly. The

change of volume imthis-chamber causes gas to be alternately sucked inand expelledthrough the nozzles 26 and 28. As'the diaphragm movesupwardly, gases are expelled through both nozzles 26 and 28 to createthe jet to impel the inert medium through the conduit l6, and when thediaphragm moves downwardly gas enters the chamber between the diaphragm23 and the cup 2| through both nozzles 26 and 28. The gas sucked intothe nozzle mostly enters from a plane at right angles to itslongitudinal dimension while that which is expelled moves forward in thedirection the nozzle is pointing, and when the diaphragm vibrates at arather rapid rate; (for example, when the magnet is energized by a 60cycle, A. C. current) gas leaving the nozzle has the appearance ofpractically a continuous jet. This jet causes the gas to move forward inthe conduit l6 and over the remainder of its circuit as indicated by thearrows in Figure 1.

In the arrangement shown, the cup-shaped member 2| is shown as havingconsiderable volume but this is for the purpose of illustration only andin actual practice the cup is made as shallow as possible in order tokeep the volume or the, chamber between it and the diaphragm small,since this aids in causing a pumping action through the nozzle eventhough the diaphragm movement is small. Since the gas is drawn into andexpelled from the chamber in which the armature is located, the constantchange of gas in-this chamber acts to cool the armature.

As can be seen, the inert medium circulator shown provides anelectro-mechanical circulator unit in which a portion of the field coreextends through the walls of the system adjacent to the movable elementwhich is hermetically sealed within the walls of the system so as toprovide a" good magnetic circuit for the magnetic flux generated by thefield coil 38 and at the same time is separated from the remainder ofthe sysi'orm both an electrical and a mechanical function.

In the embodiment shown in Figure 3, the system is in all respects likethat described in relation to Figure 1 with the exception of the inertmedium circulating unit, and like reference characters designate likeparts of the system with the exception of the circulator unit which isgenerally designated by the reference character 40. Welded to the upperinterior walls of the absorber A is a thin cup-shaped member 4| having ajet tube 42 integrally connected therewith and extending through thewalls of the absorber into the tube It. Welded or otherwise secured tothe interior of the cup-shaped member 4! is a diaphragm 43 having anarmature 44 riveted or otherwise secured thereto. Welded or otherwisesecured to the upper end of the absorber A is a second cup-shaped member45 having a tube 46 integrally connected therewith and extendinglaterally therefrom. Welded to the end of the tube 46 and extendingthrough the walls of the tube I1 is a tube 41 with a downwardlyextending jet nozzle 48.

The field structure of the circulator unit is in all respects like thatdescribed in Figure 2 andcomprises a leg 49 extending through the wallsof the cup member and separated therefrom by a non-magnetic ring 50. Theleg 49 is suitably secured to a yoke 5| of laminated me- P .tallicmaterial and an energizing coil 52 surrounds the leg 49. The portion 53of the cupshaped member 45 is made of magnetic material and theremainder is made of non-magnetic material such as some of the wellknown non-magnetic stainless steels.

When the coil 52 is energized, the magnetic circuit includes the yoke5|, the leg 49, the armature 44 and the portion 53 of the walls of thecup member between the outer edges of the yoke 5i and the non-magneticring 58.. 7

When the diaphragm 43 is drawn upwardly the volume of the chamberbetween the diaphragm and thecup-shaped member 45 decreases in volumeand forces a jet of gas from the nozzle 48 as shown by the straightarrow, at the same time, the volume of the chamber between the diaphragm43 and the cup-shaped member 4i increases in volume and gas is drawninto the chamber through the nozzle 42 from the sides or the nozzle asshown by the curved arrows. When the diaphragm 43 resumes its normalposition areverse action takes place, that is, gas moves v into thenozzle 48 from the sides as shown by the curved arrows and is forced outof the nozzle 42 as shown by the straight arrow.

A rapid reciprocation of the armature 44 will cause what appears to be acontinuous jet of gas from the nozzle "into the tube It impelli'ng whichthe moving parts of the unit are hermetically sealed within the walls ofthe system and the field structure is located outside the walls of thesystem with a portion extending through the walls and forming a portionthereof and at the same time forming a portion of the magnetic circuitwhich is separated from the remainder of prises upper and lower casingunits BI and 62 welded together at 63. It will of course be understoodthat gas circulator unit 80 can be substituted for circulator unit II inFigure 1. Inlet and outlet tubes GI and 65, respectively, are integrallyconnected to extensions 86 and 81 of the casing sections 82 andil,'respectively. Mounted to rotate on suitable bearings 68 within theinterior of the casing is an induction disc rotor 89 having fan bladesHi integrally connected therewith.

Located in the exterior of the casing wall are electro-magnetic coremembers II and I! made of laminated magnetic. material. these coremembers are welded to sections ll of magnetic material forming portionsof the casing wall separated from the remainder of-the casing walls byrings "of non-magnetic material. The section II and the rings ll ofnon-magnetic material are welded to each other and to the casing sectionBI and .82. Field coils II ,and I8 are provided for the field cores IIand 1!,respectively. A condenser 'Il-is connected in series with fieldcoil II and in parallel with field coil I! so that when the coils areenergized by an alternating current the magnetic flux excited by onecoil magnetic ring between the portions of the field core extendingthrough the system walls and the remainder of the walls may be made ofwell known non-magnetic nickel chromium steel alloys. I

While I have shown but a few embodiments of my invention, it isunderstood that these embodiments are to be taken as illustrative onlyand not in a limiting sense. I do not wish to be The ends of limited tothe exact structure shown and described, but to include all equivalentvariations thereof except as limited by the scope of the claims.

I claim:

1. A pump structure suitable for use in the inert gas circuit of anabsorption refrigeration apparatus comprising a casing housing avibratable diaphragm, a gas conduit communicating with said casing, agas nozzle having a discharge portion co-axial with a part of saidconduit and so arranged with respect to said diaphragm that vibrationthereof will alternately withdraw gas from the lateral sides of thenozzle discharge and elect gas axially thereof, and means for actuatingsaid diaphragm including an electro-.

magnet having a core with a tapered end, a cor-- responding opening insaid casing, and means securing said core in said opening and inoperative position with respect to said diaphragm whereby said. casingis sealed against the escape of gas.

2. A pump structure suitable for use in the intion co-axial with a partof said conduit and so will be displaced in phase from that excited bythe other coil so as to produce in effect a rotating magnetic fieldwhereby the induction disc I! will be rotated which in turn will rotatethe fan blades II and create a circulation of the'gas in its circuit.

"As in the other modifications it can be seen that the field coresextend "through the casing walls and are separated from theremainingportion of the casing walls by non-magnetic material so as to provideamagnetic path for the flux generated by the field coils without unduemagnetic flux leakage to other parts of the casing walls and theportions of the field cores which extend through the walls of the casingform a part of the'casing walls to prevent the escape of gas therefromunder the high pressures within the interior of the system so that theseportions of the field cores perform both a an electrical function.

It is to be understood that according to this invention the gascirculator unit of Figures 4 and 5 may be substituted for. that ofFigure 1.

In absorption refrigerating systems of the type shown, the pressuresthroughout the entire systern are substantially the same so that onlyslight force need be applied, sufiicient only to overcome mechanical andarranged with respect to said diaphragm that vibration thereof willalternately withdraw gas from the lateral sides of the nozzle dischargeand eject gas axially thereof and means for actuating said diaphragmincluding an electro-magn'et having an outer shell and an inner core,said core having a tapered head, a correspondingly shaped butlarger-opening in the casing opposite the diaphragm, non-magneticmaterial filling the space between said tapered end and said opening,

the inert medium in its circuit comprising a 685- ing forming a portionof the walls of said circuit,

a movable element hermetically sealed within said walls,electro-magnetic means positioned outside said walls. said walls beingdivided into alternate circular sections of magnetic and nonmagneticmaterial, one of. said magnetic sections forni'ingpart of the circuit ofsaid electromagnetic means and said non-magnetic section preventing fiuxleakage from said electro-magnetic means into other parts of said inertgas circuit.

4. In combination, an absorption refrigerating apparatus lraving aboiler, an absorber, and an evaporator, conduits connecting saidboiler.absorbet and evaporator to form an inert gas circuit and a solutioncircuit. an inert gas in said inert gas circuit, an electro-mechanicalcirculating unit for circulating said inertgas in said inr to iorm acircuit for the g between the evaporator and the absorber, and-an.electm-mechanical forming a portion-'0!- V electro-magnetle means havinoppositely racing polar projections position outside ert gas circuit,said circulating unit comprising a rotary element hermetically sealedwithin the walls of said apparatus and electro magnetic means outsidesaid walls opposite said rotary element, said walls being so constructedas to 'form part or the magnetic flux path for said electromagneticmeans, said part being-separated from other portions of the wall of saidapparatus by non-magnetic material, and' means connected to.

said inert gas circuit adjacent said unit and operable to 'by-passliquid which may be present in said circuit around the unit and torsaidsolution circuit. 7

5. In combination, an absorption refrigerating apparatus having anevaporator'and an absorbsorber to form a circuit for the circulation ofinpositioned intermediate of said oppositely facing polar projections,said walls including magnetic material beneath said projections and non-Y magnetic material substantially magnetically isolating saidprojections from the remainder of said walls, said magnetic materialforming part of the 7 er, conduits connecting said evaporator and abertgas between the evaporator and the absorber, and an electro-mechanicalcirculator ior circulating the inert gas in its circuit comprising acasing forming a portion of the'walls 0! said circuit,- a movableelement hermetically sealed within said'walls, electro-magnetic meanspositioned outside said walls, said walls being divided into alternatecircular sections of magnetic and non-magnetic material, one of saidmagnetic sections forming part-oi the fluxeircuit'oi saidelectro-magnetic means and said non-magnetic section preventing fluxleakage from said electro-magnetic means into other parts or said inertgas circuit, and means connected to the inert gas circuit adjacent saidunit at a point between the unit and said evaporator and operable tobypass liquid around the unit.

6.1 In combination, an absorption refrigeration apparatus including anabsorber. an evaporator,

an inert gas" circuit between said absorber and circuit of saidelectro-magnetic means and said non-magneticmaterial preventing fluxleakage from said electro-magnetic means into other parts of said inertgas circuit. 7

8. In combination, an absorption refrigerating apparatus havingbinevaporator and an absorber, conduits connecting said evaporator andabsorber to form a circuit for thecirculation of inert medium betweenthe evaporator and the absorber, and an electro-mechanical circulatorfor circulating the inert medium in its circuit comprising a casingforming/a. portion of the walls of said circuit, said casing" wallsbeing formed of magnetic material and nonmagnetic material, non-magneticmaterial I being positioned so as to. substantially magnetically isolatethe magnetic material V rately from said casing evaporator including agas heat exchanger, an-

electro-mechanical gas circulator unit in said gas clrcuit'at a pointbetween said heat exchanger and said absorber, said unit comprisinga'rotary element within said circuit, electro-magnetic means toractuating the rotary element located outside said circuit and oppositesaid rotary element, 2. portionoi'the' walls oi said eircuitiorming partof the magnetic flux path between said electro-magnetic means and saidrotary element,

said part being separated from other wall portions of said circuit bynon-magnetic material, and liquid conveying means connected to the inertgas circuit at a point between said unit and said heat exchanger forlay-passing liquid around theunit and thereby preventing saidliquidirom' contacting said rotary element,

'l; Incombinaticn, absorption refri erating apparatus having anevaporator and an absorber, conduitsconnectlng said evaporator andabsorber circulation of inert gas circulator circuit the walls ofmmicuve rotatable elemch and formed separately comprisingsa casing.

. remainder oi the the circuit of said saidwalls,an'

m its material .a e from parts of said inert-gas circuit, said magneticand from the remainder of the casing walls, a movable element withinsaid casing walls adjacent said magnetic material, electro-magneticmeans formed sepawalls for actuating said movable element to circulatethe inert medium. said-means having polar projections positioned againstsaid-magnetic material whereby said forms a part 0! the circuit of saidelectro-magnetic means and'said non-magnetic material prevents fluxleakage from said into other parts of said inert gas circuit.

ll, Incombination, an absorption refrigerating and an and absorber toform a, tion. of inert medium between the evaporator and the absorber,and an electro-mechanical circulator for circulating the inert medium inits circuit comprisi a, cas g forming a portionot the walls of saidcircuit, said casing walls being formed of magneticmaterial andnonmagnetic material, said non-magnetic material being positioned so asto substantially magnetically isolate the magnetic material from thecasing walls, a movable element within said casing walls adjacent ,saidmagnetic material, electro-magnetic means from said casing walls foractuating said movable element to circulate the inertinedium, saidmeanshaving polar projections positionedagainst said magnetic materialwhereby said magnetic material forms a electro-magnetic means and saidnon-magnetic said electro-magnetio non-magnetic material being welded toeach other and to the walls or the apparatus to form a-hermeticallyclosed eem n some.

partof' I

